Thermostatic liquid-regulator.



W. EAST, A. E. DOBBS & J. S. HOWKINS- THERMOSTATIG LIQUID REGULATOR.

APPLICATION FILED IEB.11, 1910.

1,011,041. Patented Dec.5,1911.

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COLUMBIA PLANDGRAPH 120., WASHINGTON. D1 1:.

W. EAST, A. E. DOBBS & J. S. HOWKINS.

THBBMOSTATIG L'IQUID REGULATOR.

APPLICATION FILED FEB.11, 1910.

' 3 SHEETS-SHEET 2.

PatentedDec. 5, 1911.

W. EAST, A..E. DOBBS & J. S. HOWKINS. THERMOSTATIG LIQUID REGULATOR.

APPLICATION FILED FEBJI, 1910.

1, 01 1 ,041 Patented Dec.5, 1911.

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6 Warm 1/1 trap STATES PATENT WALTER EAST, OF BOURNEMOUTH, ENGLAND,ARCHIBALD EDWARD DOBBS, 0F CASTLE DOBBS, NEAR CARRJEGKFERGAS, IRELAND,

FULHAM, LONDON, ENGLAND.

AND JOHN SHIRLEY HOWKINS, OF

THERMOSTATIG LIQUID-REGULATOR.

Specification of Letters Patent.

Application filed February 11, 1910.

To all whom it may concern:

Be it known that we, WALTER EAST, J. P., of D01 Peris, Surrey Road,Bournemouth, in the county of Hants, England, ARCHI- BALD EDWARDDoBBs,'J. P., of Castle Dobbs, near Carriokfergas, county Antrim,Ireland, and JOHN SHIRLEY HOWKINS, of 40 Walde-' mar Mansions, Waldemaravenue, Fulham, in the county of London, England, engineer, all subjectsof the King of Great Britain and Ireland, have invented certain new anduseful Improvements in and Relating to Thermostatic Liquid-Regulators,of which the following is a specification.

This invention relates to improvements in thermostatic apparatus formaintaining a constant liquid level in steam generators and the like.

In such constructions as have been hitherto proposed the operatingelement, by the expansion and contraction of which the valve or the likecontrolled by the thermostat is moved, has been exposed externally tothe furnace gases and filled internally with water or steam according tothe level of the water in the boiler, the variation in temperature ofthis element being obtained by the difl'erence between the rates ofabsorption of heat from the element by the steam and water whichalternately fill the greater part of its interior. As it was necessarythat the thermostat should be placed in the path of the furnace gases ata height corresponding with the desired water level in the boiler, it isnot applicable to all types of boilers. Further the operating elementwas gradually burned away by the fire and an explosion was likelytherefore to occur as the interior of the element was at the full boilerpressure, also being placed thus in the furnace the thermostat wasdifiicult to adjust and repair.

The object of the present invention is to provide a thermostaticapparatus for maintaining a constant liquid level, which shall not beburned away in operation and shall. be of simple and easy construction.

The invention consists in a thermostatic controlling device in which theoperating element consists of a tube anchored at one end through whichpasses fluid at a substantially constant temperature, said tube beingsurrounded externally by a liquid or gas or vapor, the change in lengthof said tube consequent upon change in its temperature being determinedby the amount of surface of said tube exposed externally to said liquidor gas or vapor.

The invention also consists in a thermostatic controlling device as setout above, arranged to maintain a constant water level in a boiler inwhich steam superheated to a constant temperature is passed through theinterior of said tube which is surrounded externally by water and steam,said tube by its extension or contraction in accordance with the changesof water level in said boiler controlling means whereby the superheatedsteam passing through it is led into the steam supply pipe from theboiler or to a pump or the like supplying feed water thereto, or intothe atmosphere or the condenser.

The invention further consists in the im proved thermostat and feedwater controlling devices hereinafter described.

Referring now to the accompanying drawings, Figure 1 shows sideelevation of one form of our improved thermostat as used for maintaininga constant water level in a boiler. Fig. 2 is a section on the line A Aof Fig. 1. Fig. 3 is a diagrammatic sketch showing our thermostat asplaced within a boiler. Fig. 4 is a vertical section and Fig. 5 is asectional plan of part of a Cornish boiler showing our improvedthermostat arranged outside the boiler at the front. Fig. 6 shows a sideelevation of another form of our improved thermostat fixed outside aboiler as used for maintaining a constant water level in a boiler.

In carrying this invention into effect according to the constructionshown in Figs. 1 and 2, a back-plate, a, is secured rigidly to theboiler shell, I), in any convenient position at the normal water levelby two or more rods or bars, 0. Into this backplate, a, there screws atube d,made of any suitable material, preferably with a high coefiicientof expansion, and this tube, (Z, passes through a suitable opening inthe boiler shell, 6, and operates a valve controlling the supply ofsteam to a feed water pump, injector or the like in a manner to behereinafter described. Into the end of the tube, 0?, which is attachedto the backplate, a, steam at a temperature above that corresponding tothe pressure of the steam in the boiler is led by a pipe, e. This steammay be taken from the boiler in which the Water level is to bemaintained constant and superheated as shown in Fig. 3 or the steam maybe taken from an independent source so long as its temperature is higherthan that of the steam within the boiler. Attached to the boiler shell,Z), by a nipple union 7, or other suitable means is a steam tightcasing, g. The tube, (Z, passes through the nipple union, f, which is asliding fit over the former. At one end of the casing, g, is a screwplug, h, to which is fulcrumed a lever, 2'. The other end of the casing,g, is also preferably closed by a screw plug, Screwed into the side ofthe casing, g, at or near the end remote from that at which the lever,Z, is fulcrumed is another casing, m, in which works a valve, a,controlling two ports, 0 and p, one of which communicates with a pipe,leading to the steam main, 1", and the other communicates with a pipe 8,leading to a feed water pump or the like (not shown) as indicated inFigs. 3 and 1. The valve, n, is made of such length that when in itsmid-position, it is just short of the ports, 0 and 79, at each end asshown in Fig. 1. The valve, n, is made in one with a spindle, t, onwhich is provided a guide, u. Both the guide, a, and the valve, n, arepierced to allow the steam to pass to the other side thereof. The end ofthe valve spindle, t, screws into a forked end, c, in which is a pin, w.By this means the distance between the centers of the pin, w, and thevalve n, can be adjusted, a nut as, being provided on the valve spindle,t, to act as locking means when so adjusted. The pin, w, engages with aslot, y, in the end of the lever, 2', remote from its fulcrum. At anintermediate point in its length, but preferably near its fulcrumed end,the lever, 2', is secured to the tube (Z, in any suitable manner, aconvenient construction is hereinafter described. The end of tube, (Z,which extends outside thev boiler shell, 5, is made of a slightly largerdiameter than the rest of the tube this end being screwed into a ring,2, having two pins, 1, arranged diametrically opposite to each other andextending outward. A loop is formed through the lever, i, of sufiicientsize to admit freely the ring, 2, and the two pins, 1, engage withholes, 2, in the lever, 2'. By providing the casing, g, with a screwplug, 8, opposite the end of the tube, (Z, it is then possible tounscrew the latter from the ring, 2, and the back plate, a, and sowithdraw it.

The action of the thermostat and valve is as follows :Steam is led fromthe steam space of the boiler for instance from the steam dome, 4, by apipe 5 to a superheating coil, 6, placed in any convenient place in thepath of the furnace gases. From this superheating coil, 6, the steam isled by the pipe, 0, into the interior of the tube, (Z, and thence to thecasing, g. The tube (Z is placed at the normal level of the water in theboiler and while this level is maintained, the tube, (Z, is justimmersed in the water and the length of this tube, (Z, is determined bythe temperature of the superheated steam within it and the rate ofabsorption of heat by the water without, the valve being then adjustedso that the steam passes from the casing, g, by port, 0 and pipe, 9,into the main steam pipe, r. Should the water however fall below thislevel, the tube, (Z, is immersed in steam and the rate of absorption ofheat from the superheated steam within the tube, (Z, is less than therate of absorption when said tube is immersed in water. This tubeconsequently gets hotter and expands moving the valve, a, in such amanner that steam from the casing, g, escapes by the port, p, and pipe,8, to a pump or the like (not shown) supplying feed water to the boiler.

In a modification of thisarrangement as shown in Figs. 4; and 5, thethermostat is arranged outside the boiler, the superheated steam passingthrough a grid, 11, or the like arranged at the normal water level ofthe boiler and then into the tube, (Z. 7 It will be seen that thetemperature of the steam in the tube, (Z, will depend on whether thegrid, 11, is immersed in water or steam. The expansion and contractionof the tube, (Z, controls the supply of feed water in a similar mannerto that already described with reference to Figs. 1 and 2. V

In the modification shown in Fig. 6, the tube, (Z, is mounted in twouprights, 12, attached to a frame, 13, which frame also carries thecasing, g, and the feed water controlling means. The end of the tube,(Z. remote from the casing, g, is rigidly held in its upright by twonuts, 14, by means of which also the length of the tube, (Z, can beadjusted. Into one end of this tube, superheated steam is led afterhaving passed through a grid, 11, and the other end of the tube, (Z, isclosed by a cap, 15, or thelike. Steam from an independent source can beused if required. A pipe, 16, leading to the steam main, 1",communicates with this end of the tube, (Z, in any convenient manner soas to permit circulation of the steam through the tube, (Z. In the sideof the casing, g, opposite the end of the tube, (Z, is an opening havinga flange, 17 To the cap, 15, on the end of the tube, (Z, there screws amember, 18, reaching nearly but.

not quite up to the opening on the casing, g, and having a flangesimilar to the flange 17 These two flanges are connected by two dishedthin metal diaphragms, l9, bolted or otherwise secured together at theircircumference. Extending into the casing, g, and formed preferably inone with the member, 18, is an extension, 20, having a forked endprovided with holes. The lever, i, is in this construction fulcrumed atan intermediate point in its length to a support, 22, formed in thecasing, g. The holes on the extension, 20, of the member, 18, engagewith pins, 28, on the end of the lever, 2'. The other end of this leveris in contact with the stem of a valve, 24, which controls a passage,25, communicating between the interior of the casing, g, and a chamber26. Into this chamber, 26, the feed water is conducted by a pipe, 27,and thence by another pipe, 28, past a nonreturn valve, 29, to theboiler. A spring, 30, normally presses the valve, 24, on to its seatthus cutting off the communication between the passage 25 and thechamber 26. Assume that the water is up to the level of the grid, 11,the steam entering the tube, (i, will therefore be at its lowesttemperature. The tube will also be at its minimum length and the valve,24, will be pressed upon the lever, 2'. The feed water will then be ableto escape by the passage, 26, into the interior of the casing, g, whenceit is conducted away by a pipe, 31. Should the water level however fall,the temperature of the steam will be higher and the tube, (Z, willconsequently expand. The spring, 30, will then close the valve, 24, andthe water will then be fed into the boiler until the normal level hasagain been reached. This form of the feed water controlling device mightalso be used when the tube, d, is placed within the boiler.

Although we have described our thermostat in conjunction with a boilerfor maintaining a constant water lever therein, we do not confineourselves to this application. For instance, it can be applied tobrewing and distilling plants and in plants for the concentration ofliquids by evaporation and re-condensation for the purpose ofmaintaining a liquid at a constant level.

It will be seen that many modifications may be made in the method ofcarrying this invention into effect without in any way departing fromthe spirit of the same.

Having thus described our invention, what we claim as new and desire tosecure by Let ters Patent is 1. In an apparatus for regulating the levelof the liquid in a vapor generator, a thermostatic element through whicha superheated fluid is always passing, a part of said element beingsituated at the desired liquid level, the operation of said elementdepending upon the rate of flow of heat from the superheated fluid tothe vapor and the liquid respectively in accordance wit-h the liquidlevel in said generator.

2. In an apparatus for regulating the level of the liquid in a vaporgenera-tor, a thermostatic element through which a fluid is alwayspassing, means for superheating said fluid and means for holding saidelement at the liquid level required in the generator, the meantemperature of said element itself thus depending upon the physicalstate of the surrounding fluid, whether liquid or gaseous, whereby onthe liquid level in said generator changing, the mean temperature ofsaid element is affected, valve means operated by the consequent changein length of said element to eflect the readjustment of the liquid levelin the generator.

8. In an apparatus for regulating the level of the liquid in a vaporgenerator, a thermostatic element through which a fluid is alwayspassing, means for superheating said fluid and means for holding saidelement at the liquid level required in the gen erator, one end of saidelement being fixed, the mean temperature of said element itself thusdepending upon the physical state of the surrounding fluid, whetherliquid or gaseous, valve means operated by said element and acting tocontrol the liquid level in said generator, whereby on the liquid levelin said generator changing the mean temperature of said element isaffected and the consequent change in length utilized to efl ect there-adjustment of the liquid level in the generator.

4. In a vapor generator, a thermostatic device having an operatingelement, the external surface of which is in contact with the liquid orthe vapor in said generator according to the liquid level therein, afluid always passing through said element and means for superheatingsaid fluid, the vapor absorbing heat from the superheated fluid at adifferent rate than the liquid whereby changes in the liquid level inthe generator cause said element to expand or to contract.

5. In a vapor generator, a thermostatic device having an operatingelement, the external surface of which is in contact with the liquid orthe vapor in said generator according to the liquid level therein,afluid always passing through said element and means for superheatingsaid fluid, the vapor in the generator absorbing heat from said fluid ata different rate than the liquid whereby changes in the liquid level inthe generator cause said element to expand or to contract and means forutilizing'said expansion or contraction to effect the readjustment ofthe liquid level in the generator.

6. In a vapor generator, a thermostatic device having an operatingelement placed at the level of the liquid in the generator, asuperheated fluid always passing through said element and imparting heatto the surrounding liquid or vapor and means for utilizing the changesproduced on said element by the physical state of the surrounding fluidto maintain a constant liquid level in the generator.

7. In conjunction with a liquid evaporating element; a thermostat devicefor controlling the supply of liquid to said element, comprising incombination a tube through which a superheated fluid is always passing,said tube being fixed at one end, means for supporting said tube in-thevapor of the liquid within the element, pump means delivering liquid tosaid evaporating element, and pump controlling means connected with thefree end of said tube, whereby the amount of liquid delivered to saidelement depends on the amount of the surface of said tube exposed to theliquid and the vapor thereof.

8. In conjunction with a liquid evaporating element, a thermostaticdevice for controlling the supply of liquid to said element, comprisingin combination a tube fixed at one end, through which a superheatedfluid is always passing, means for supporting said tube in the vapor ofthe liquid within said element, means delivering liquid to saidevaporating element, lever means attached to the free end of said tubeand controlling the delivery means, whereby the amount of liquiddelivered to the evaporating element depends on the amount of surface ofsaid tube exposed to said liquid, or the vapor thereof.

9. In conjunction with a liquid evaporating element, a thermostaticdevice for controlling the supply of liquid to said element, comprisingin combination a tube fixed at one end and through which a superheatedfluid is always passing, means for supporting said tube in the vapor ofthe liquid within said element, means delivering liquid to saidevaporating element, lever means attached to the free end of said tube,a valve controlled by said lever means, whereby on the liquid level insaid evaporating element falling, said tube expands and moves the valveso as to admit of the fluid flowing through the tube to said deliverymeans.

In testimony whereof, we afiiX our signatures in presence of twowitnesses.

WVALTER EAST. AROHIBALD EDIVARD DOBBS. JOHN SHIRLEY HOWKINS.

Witnesses to the signatures of the said Walter East and John ShirleyHowkins:

DANIEL D. BAIRD, P. A. OUTI-TWAITE. WVitnesses to the signature of thesaid Archibald Edward Dobbs:

EDWARDS HARVEY, SOPHIA E. DOUGLAS.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of latents, Washington, D. C.

